Conventionally, as pneumatic tires (tires, hereafter) to be fitted to a passenger car and the like, there has been known a tire in which groove walls of land portions formed by circumferential grooves extending in a tire circumferential direction are provided with recessed portions formed in a tread width direction to improve a drainage performance of water entering the circumferential grooves (Patent Document 1, for example).
Specifically, the recessed portions are provided at predetermined intervals in the tire circumferential direction and groove walls of the recessed portions are formed in half-moon shapes in a tread surface view. In this tire, water flowing in the circumferential grooves tends to flow more smoothly along the half-moon shapes of the recessed portions than in the case where the recessed portions are formed in rectangular shapes in the tread surface view, and the drainage performance is thereby improved.